User guide

5–2 Chapter 5: 2D Median Filter MegaCore Function
Parameter Settings
Video and Image Processing Suite January 2013 Altera Corporation
User Guide
Error Recovery
The 2D Median Filter MegaCore function resolution is not configurable at run time.
This MegaCore function does not read the control packets passed through it.
An error condition occurs if an
endofpacket signal is received too early or too late for
the compile-time-configured frame size. In either case, the 2D FIR Filter always
creates output video packets of the configured size.
If an input video packet has a late
endofpacket signal, then the extra data is
discarded. If an input video packet has an early
endofpacket signal, the video frame is
padded with an undefined combination of the last input pixels.
1 For more information about the stall behavior and error recovery, refer to “Stall
Behavior and Error Recovery” on page 1–3.
Latency
Table 5–2 lists the approximate latency from the video data input to the video data
output for typical usage modes of the 2D Median Filter MegaCore function. You can
use this table to predict the approximate latency between the input and the output of
your video processing pipeline.
The latency is described using one or more of the following measures:
■ the number of progressive frames
■ the number of interlaced fields
■ the number of lines when less than a field of latency
■ a small number of cycles O (cycles)
The latency is measured with the assumption that the MegaCore function is not being
stalled by other functions on the data path (the output ready signal is high).
1 The latency associated with the initial buffering phase, when a MegaCore function
first receives video data, is not included.
Parameter Settings
Table 5–3 lists the 2D Median Filter MegaCore function parameters.
Table 5–2. 2D Median Filter Latency
Mode Latency
Filter size: N × N
(N–1) lines +O
(cycles)
(1)
Note to Table 5–2:
(1) O refers to a small number of clock cycles, and is not of zero value.
Table 5–3. 2D Median Filter Filter Parameter Settings (Part 1 of 2)
Parameter Value Description
Image width 32–2600, Default = 640 Choose the required image width in pixels.
Image height 32–2600, Default = 480 Choose the required image height in pixels.